Improvement in screw-taps



T. S. WILD.

Screw-Tap. No. 60,559. Patent ed March 9, 1875 THOMAS S. WILD, OFCHICAGO, ILLINOIS.

IMPROVEMENT IN $CREW-TAPS.

Specification forming patt of Letters Patent No. 160,559, dated March 9,1875; application filed December 22, 1874.

To all whom it may concern:

Be it known that I, THOMAS SAMUEL W111), of Chicago, county of Cook,State of Illinois, have invented an Improved Tap for CuttingScrew-Threads, of which the following is a specification, referencebeing had to the ac companying drawings which form a part thereof.

The object of my invention is to facilitate the adjustment of the dieswhich cut the screw-thread, so that the tap can be adjusted to anyposition or removed from its work.

The nature of my invention consists in the novel construction of thedie-holder, in comhination with the sliding piece I; and, also, in asort of compound lever, with which the die-holder is operated; incombination with the same, the sliding. stop, for operating the diesautomatically; and in the novel construction of the tap-stock, ashereinafter more fully described.

In the annexed drawing, Figure 1 represents a longitudinal sectionalview of the tapstock, showing the compound lever and the edge of thedie-holder. Fig. 2 represents a longitudinal section of the tap-stock,showing a side view of the die-holder and dies; and Fig. 3 shows an endview of the tap-stock with the levers and end plate removed.

Arepresents the tap-stock, slotted and bored out at its end to receivethe die-holder B. G are the dies, having a dovetailed tenon on one edge,which fit and slide in a correspondinglyshaped groove in the slantingedge of the dieholder. D is a pointed lever, pivoted at E. The short endof the lever extends into the recess F in the tapstock, and straddlesthe stem of the die holder, in such a manner as to operate it, ashereinafter more fully described. G is a second hand-lever, pivoted tothe long arm of the lever D at H; andI is a sliding piece, pivoted tothe short arm of the lever G at J. This sliding piece passes beneath thestem of the die-holder B, and holds it thrust out when the tap is inoperation, the stem of the tap resting upon the sliding piece I.

When it is desired to remove the tap from its work, by raising the leverG the slide piece I is first withdrawn from beneath the stem of thedie-holder B, when the long arm of lever G strikes the long arm of thelever D, as shown in Fig. 1, and then the lever D vibrates upon itspivot E, and forces the dieholder to reoede, as shown by dotted lines inFig. 2. The dies 0 slide in the grooves in the edges of the die-holderas the dieholder recedes, as above described, and because of of thetapering form of the die-holder, as shown, the dies are drawn entirelywithin the tap-stock, as shown by dotted lines in Fig. 2. The tap can beinstantly removed from its work by the operator adjusting the lever, asabove described, which withdraws the dies from the thread.

K is a plate screwed into the end of the tap-stock, to hold the dies inplace and to cover the working parts of the tap. L is a spring, attachedto the lever D and resting upon the sliding piece I, to hold it inplace. M is a strengthening-ring shrunk upon the tap-stock, tostrengthen it; and N is also a ring or band attached to the tapstock, tostrengthen it and to make a bearin g for the lever 1). O is a lever,pivoted at P; and Q is a sliding rod, which is pivoted to-the short armof the lever O, and slides in the hearing or socket R. The long arm ofthe lever 0 extends beneath the lever G.

The object of this device is to set the sliding rod Q at such point,with reference to the cutters, that it will, at a certain point, strikethe nut or other article being supplied and operate the lever Q, which,striking against the lever G, will, through it, withdraw the dies intothe position shown by the dotted lines in Fig. 2, as above described.

S is a thumb-screw, for gaging the sliding rod Q to have it stop the tapfrom cutting at the desired point. The end of the tap-stock A is slottedto the depth of the wide part of the stay of the die-holder B, and.pieces T are put into this slot, to form guides for the die-holder Bbefore the ring M is shrunk upon said tap-stock. U is a spring restingupon the top of the lever D; and V, a spring resting on the short arm ofthe lever O, to be held there in place.

What I claim, and desire to secure by Letters Patent, isr 1. Thecombination of the tap stock A providsd with a transverse recess oropening to 3. The combination of the sliding rod Q, the receive thesliding piece I, the die-holder B, levers O and G, and sliding piece I,substanend the sliding piece I, substantially as and tially as and forthe purpose specified.

for the purposes specified. THOMAS S. WILD.

2. The combination of the die-holder B, the Witnesses: compound levers Dand G, and sliding piece L. A. BUNTING,

I, substantially as described. HEINRICH F. BRUNS.

